Spring is here. The first migrants have crossed the Piscataqua River and entered Maine. Blackbirds show up earliest, and flocks of grackles and cowbirds arrived in southern Maine last week. Some flocks have already pushed northward.
Owls are hooting. Great horned, barred and saw-whet owls are pairing up and defending territories. One of my neighbors reports that the saw-whet owl he heard calling behind his house last year is calling again this year. Hairy woodpecker pairs are drumming the daylights out of the oaks above my garage. Ducks started pairing up weeks ago. I witnessed a pair of peregrine falcons harassing pigeons over St. Joseph’s Hospital in Bangor last week. Winter is over.
But what a weird winter it was. It started with a massive wave of Canadian breeders moving south, washing over Maine in December. Most continued on. There are still a few pine grosbeaks, evening grosbeaks and common redpolls in the area, but crossbills, purple finches and pine siskins almost completely deserted northern and eastern Maine. Many backyard bird feeders are hanging limp, ignored.
However, the exodus from Canada has produced a couple of pleasant surprises. One is an influx of short-eared owls. These crow-sized owls are a few inches smaller than our resident barred owls. Unlike our woodland owls, they hunt in the open, over grasslands and marshes, using a flight style that is similar to northern harriers. They float slowly over the field, twisting and turning swallow-like, in search of rodents, their preferred food. They also take birds and bats occasionally.
The short-eared owl name comes from feather tufts on the head that look like tiny ears, viewable only from a close distance. They are ground nesters, and a tiny handful of historic breeding records exist in Maine, though none recently. Sackville, New Brunswick is surrounded by a series of tidal marshes and associated grasslands called the Tantramar, which make ideal habitat for short-eared owls. It’s quite the adventure to park on the interior roads and watch what happens. By day, northern harriers float over the field. Toward sundown, the short-eared owls come out and replace them. The owls are crepuscular, meaning that they hunt on the edges of daylight at dawn and dusk, when they are also easy to see. In winter, a hungry owl will hunt at midday.
A slew of short-eared owls have been sighted around Portland this winter, especially at the Jetport and in Scarborough Marsh. Other hot spots have included the boat launch at Messalonskee Lake in Belgrade, a blueberry field in Appleton, at least one sighting near Bangor International Airport and multiple sightings in Hancock County.
It’s also been a good winter for northern shrikes. I’ve seen six so far. I barely saw any over the last three winters. Most reported sightings were in eastern and southern Maine, probably because that’s where the people are. Shrikes seem to be popping up everywhere. Look for them in the tippy-top of trees.
The northern shrike is that rare thing: a predatory songbird. You’d think I would learn to be careful about using semi-scientific terms like “predatory songbird,” because I never know when I might have to explain myself. I used the term in a Facebook group, and somebody promptly challenged me. After all, many songbirds are predators. They prey on insects, spiders, beetles, caterpillars and other invertebrates.
Shrikes are different. They prey mostly on vertebrates, primarily other birds and small mammals. There are over 30 shrike species in the world, but only two in North America. Loggerhead shrikes range south and west of us, and almost never wander into Maine. Northern shrikes nest across northern Canada and visit Maine in winter when food supplies dwindle at home.
Raptors have hooked bills that enable them to tear flesh. Shrikes do, too, although they are smaller than blue jays and lighter than robins. However, given the shrike’s small size relative to its prey, the bill is uniquely designed for snipping the victim’s neck, abruptly ending any inconvenient struggles.
As for being songbirds, you should hear one sing! Roughly 5,000 of the world’s bird species are considered songbirds, with vocal organs well enough developed to enable complicated and variable songs. Both shrike sexes sing, and they are most apt to do it right about now. The song is a jumble of warbles, whistles, trills and chatter, and they even throw in a few imitations of other birds. I’ve only heard them sing three times, and it was a jaw-dropping performance each time.
Bob Duchesne serves as vice president of Maine Audubon’s Penobscot Valley Chapter. He developed the Maine Birding Trail, with information at mainebirdingtrail.com. He can be reached at firstname.lastname@example.org.